Religion is supposed to be a positive moral force and help make people responsible to one another. Therefore creating larger societal bonds. Whereas drugs just make us disappear more and more into ourselves.
Well I would not advise anyone to take drugs "legal" or otherwise. As far as religion not just the "leadership" but mostly the believers themselves. I don't conceive of religion as following persons or people but God. People can and often use religion to justify all kinds of things mostly their own selfishness.
I think pain relief is a major reason people are prescribed drugs -I wonder why plants, insects and reptiles 'knoe' how and have glands or organs to produce painful toxic substance for its victims but we have no facilities in our bodies that could produce substance to give significant relief for extreme chronic pain when ya'd think that could happen. Nature is funny.